Continuously operating centrifugal machine



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H. J. VAN WEZEL Jan, 29, 1957 CONTINUOUSLY OPERATING CENTRIFUGAL MACHINE Filed May 6, 1955 Jan.. 29, 1957 H, J. VAN WEzEl. 2,779,473

coNTINUoUsLY OPERATING CENTRIFUGAL MACHINE Filed May 6, 1955 2 Sheets-Sheet 2 nited States CONTINUOUSLY OPERATING CENTRIFUGAL MACHINE Herman J. van Wezel, Hengelo, Netherlands, assignor to Koninklijke Machinefabriek Gebr. Stork & Co. N. V., Hengelo, Netherlands, a company of The Netherlands Application May 6, 1955, Serial No. 506,570

Claims priority, application Netherlands March 15, 1955 3 Claims. (Cl. ZIO- 69) ,whole height of the screen wall and said scraper device being further provided with one or more nozzles discharging a compressed medium blowing the solid particles scraped off from the screen wall towards the discharge end of the drum.

In such a continuously operating centrifugal machine part of the solid material scraped off from the screen Wall is dispersed in the drum by the compressed medium whereby the discharge of the mass is hindered. According to the present invention said drawback is removed by this that the scraper device is provided with a partition arranged parallel to the drum axis and substantially radially directed, said partition leaving a space with respect to a substantially radial wall of the scraping device, said space being located opposite to the nozzles discharging the compressed medium and said partition leaving a gap with respect to the screen wall of the drum and said arent space being closed towards the axis of the drum. With said arrangement the solid mass scraped olf from the screen wall is blown by the compressed medium into the space formed between said partition and said scraper wall towards the discharge end of the drum so that the mass cannot be dispersed in the drum.

The invention will be further described with reference to the accompanying drawings illustrating an embodiment of the centrifugal machine according to the invention.

Fig. 1 is a sectional elevation of the machine taken along the broken line l-I of Fig. 2.

Fig. 2 is a horizontal section taken along the line II-II of Fig. 1.

Fig. 3 is a horizontal section of part of the centrifugal machine on enlarged scale.

The centrifugal basket or drum 2 is secured on the shaft 1 with its hub 3. The inner wall of the drum is constituted by a screen wall 4. The outer wall of the drum 2 is conically widened in upward direction so that the liquid thrown on said wal] is moved upwards by the centrifugal action and ows over the rim 6 into the gutter 7 at the inner side of the stationary outer drum 8.

The shaft 1 is surrounded by a hollow shaft 9 which at its upper end and its lower end is guided by a bearing 10 on the shaft 1 and supported by an axial bearing 11. The hollow shaft 9 carries a drum 12 having an oval cross section and connected to the shaft by a bottom plate 13. To diametrically opposed flat boxes 1d are secured to the oval drum 12 at its largest diameter and extend throughout the height of the screen wall 4 but leave a discharge gap 15 with respect to the screen wall. Adjacent each box 14 a further box 16 is formed by a wall 17 also secured to the oval drum 12, said box 16 at its end facing the screen wall 4 being provided with a scraper 18 also extending throughout the height of the screen Wall. The Scrapers 18 at their inner side are provided with nozzles 19 directed downwards.

A cylinder 20 is secured in the interior of the oval drum 12 and carries diametrically opposed sets of sprinklers 21, so that said latter are also rotating together with the hollow shaft 9. A gutter 22 for supplying the mass to be treated discharges into the upper end of the oval drum 12 and a pipe 23 for supplying washing or treating liquid opens into the cylinder 20.

The shaft 1 which is driven by a motor or in another way hangs in a bearing block 24 supported in a rubber buffer 25. A gear box 26 is secured tothe bearing block 24 so that said box is adapted to follow the oscilla tions, if any, of the shafts 1 and 9. On the shaft 1 a toothed wheel 27 is secured which through the intermediary of two wheels 29, 30 transmits its motion to a toothed wheel 2S secured on the hollow shaft 9. The gear ratio between the toothed wheels 27 and 28 is such that the difference between the speeds of the shafts 1 and 9, which determines the duration of the treatment of the mass is very small. Preferably the gear ratio of the toothed gearing is variable in order to vary the duration of the treatment at will. The distance piece 4t) serves as a closure means or closing element for the space 44 between the wall 17 and the plate 41 at the side of the drum axis.

For supplying compressed air or another compressed medium the lower part of shaft 1 is provided with a central bore 31 communicating by some radial holes 32 with a chamber 33 to which the boxes 16 are connected.

On the end of shaft 1 a stationary stuffing box 34 is mounted and said stuffing box is provided with a connection 35 for a pipe or flexible tube supplying a compressed medium.

In the bottom plate 13 discharge openings 36 are provided near the Scrapers 18 and in the lower end of the outer wall of drum 2 openings 37 are provided. Said openings are located between guide plates 3S.

A plate 41 is secured to the wall 17 of box 16 through the intermediary of a distance piece 40 by means of bolts 42 secured in a connecting piece 43 on which the scraper 18 is slid. The plate 41 with the distance piece 40 confines a space 44 located opposite to the discharge nozzles 19 of the scraper 1S for the compressed medium.

The plate 41 together with the distance piece 4t) is adjustable in radial direction and to this end the holes for the bolts 42 are shaped as horizontal slots L35. The plate 41 is further provided with stiffening ridges 46.

The above described centrifugal machine operates as follows.

The mass to be treated is continuously delivered into the oval drum 12 by means of the gutter 22 and is uniformly distributed over the height of said drum under the centrifugal action. Due to the oval shape of the drum wall the entering mass is always guided towards the delivering boxes 14 in order to be deposited on the screen wall 4 through gap 15. The thickness of the deposited layer depends on the width of gap 15. As the screen wall 4 moves relatively to the boxes 14 the mass is continuously deposited on the wall 4 and after a relative rotation of is removed from the wall 4 by the diametrically opposed scraper 18 and blown by compressed air or another compressed medium discharged from the nozzles 19 into the space 44, so that the mass is discharged through the opening 36 provided in the bottom plate 13. In order to prevent clogging of the space 44, said latter is widened in downward direction as the width of the distance piece ill decreases towards its lower end. The removed mass entering the lower part of drum 2 is thrown into the stationary outer drum 8 through the openings 37 and collected in the funnel 3.9. The separated liquid passes through the screen wall 4 and flows over r`the rim '6 in order t'o be 'collected in the gutter 7.

:Dur-ing the separation -frorn the liquid of the mass deposited on the wall 4 said mass may be washed tby water or treated by another 'liquid discharged by sprinklers 21. By 'the centrifugal action the liquid 'is discharged with such violence that an efficient spraying of the liquid is secured.

Though in the illustrated embodiment the compressed medium is supplied by the hollow scraper box l, a plate like scraper may be used and a separate nozzle for the compressed medium may be mounted near .the scraper.

Instead of vertically the centrifugal machine according to the invention may also be horizontally mounted.

What I claim is:

1. A continuously operating centrifugal machine, com* prising a drum having a circumferential wall formed as a screen wall, an outlet at one end or the drum, feed members extending substantially along 'the whole height of the Screen wall of 4the drum and a scraper device connected to said feed members and rotatable in the drum with an angular velocity slightly dilering from that kof the drum, said scraper device extending substantially along the whole height of the screen wall of the drum and being provided with at least one `scraper and at least one nozzle for discharging a medium under pressure :for blowing the solid 'particles detached from the kscreen wall towards the outlet end of the drum, characterized in that the scraper device is provided with a substantially radial Wall, a partition arranged substantially parallel to and spaced from said radial wall to define a space therebetween, said space being located opposite to the nozzles discharging the compressed medium, there being a space between said partition and said screen wall of the drum through which the active part Vof -the scraper device ex tends, and a closing element between said partition and said parallel Wall of the scraper device for closing the space therebetween at the side of the drum axis.

2. A continuously operating centrifugal machine as claimed in claim l, characterized in that the radial width of the space formed by the partition increases towards the outlet end of the drum.

3. A continuously operating centrifugal machine as claimed in claim fl, characterized in that the partition is adjustable in radial direction with respect to the screen wall of the drum.

References-Cited inthe tile of this patent UNITED STATES PATENTS 1,572,419 Birchall Feb. `9, 1926 1,572,420 Birchall Feb. 9, 1926 2,056,886 Pecker Oct. 6, 1936 2,312,829 Bird Mar. 2, 1943 FOREIGN PATENTS 698,750 Great Britain Oct. 2l, 1953 

